1. Field of the Invention
The present invention is directed to a yaw rate sensor and a method for operating a yaw rate sensor.
2. Description of Related Art
Such sensors and methods are known, e.g., a yaw rate sensor having a substrate and a Coriolis element is known from published international patent application WO 03/058167 A1, in which the Coriolis element can be excited to a drive oscillation parallel to a first axis, and the Coriolis element is deflected by a Coriolis force along a detection direction perpendicular to the first axis, and the yaw rate sensor has force-transmitting means between the substrate and the Coriolis element in the form of compensation structures provided for compensating for quadrature bias. The Coriolis element includes a seismic mass having multiple cutouts into which electrodes of the compensation structures protrude, which are connected to the substrate. The inner circumference of each of the cutouts has an asymmetrical design, so that quadrature compensation forces are generated parallel to the detection direction as the result of appropriate wiring of the electrodes. These quadrature compensation forces are used to compensate for the quadrature bias which is superimposed on the detection motion of the Coriolis element and which occurs during the excitation of the drive oscillation due to manufacturing-related imperfections in the sensor structure. It is disadvantageous that the quadrature compensation forces are greatly dependent on the deflection along the detection direction, so that an inadvertent oscillation of the Coriolis element about its working point along the detection direction results in a change in the quadrature compensation force. As a result, the vibration sensitivity of the sensor system with respect to external interfering excitations is increased. The quadrature compensation forces, which are a function of the working point, also result in a working point-dependent electrostatic spring stiffness along the detection direction, so that the resonance frequency of the sensor system also has an undesired dependency on the working point.